Effects of isolated shoulder versus core-shoulder chain exercises on motor control and isokinetic torque in baseball pitchers with shoulder impingement syndrome: A single-blinded randomized controlled trial.

Recent biomechanical evidence suggests that shoulder impingement syndrome (SIS) is closely linked with altered core-shoulder kinetic chain, resulting pain, altered external shoulder muscle activation, and external muscle weakness. We aimed to compare the effects of conventional isolated shoulder exercise (ISE) and core-shoulder chain exercises (CCE) during isokinetic shoulder rotation in baseball pitchers with SIS. Forty male college baseball pitchers with SIS were randomly allocated to ISE and CCE groups and they performed the exercises 3 times a week for 6 weeks. The standardised numerical pain rating scale (NPRS), shoulder pain and disability index (SPADI), electromyography (EMG) amplitude, and concentric (CON) and eccentric (ECC) torques were measured. Substantial improvements in NPRS and SPADI scores were observed after CCE compared to ISE (p ≤ 0.046). Internal oblique/transversus abdominis, rectus abdominis, external oblique, serratus anterior, and infraspinatus muscle activation were significantly higher after CCE than ISE (p ≤ 0.033). CON and ECC torques were higher after CCE than ISE (p ≤ 0.002). The present findings demonstrated superior therapeutic effects of CCE in improving pain, disability level, shoulder muscle activation, and torque (muscle strength) in baseball pitchers with SIS compared to the conventional ISE, highlighting the importance of the chain exercise concept.

A Comparison of 2 Exercise Protocols in Athletes With Primary Subacromial Impingement Syndrome: A Randomized Clinical Trial.

CONTEXT: To stabilize the humeral head within the glenoid fossa during arm elevation, the rotator cuff muscles may contribute through internal and external rotation. The main purpose of the current study was to compare the acromiohumeral distance between athletes with primary subacromial impingement syndrome who received progressive resistance exercises consisting of either shoulder internal or external rotation. DESIGN: A randomized and controlled clinical study. METHODS: Thirty athletes with primary subacromial impingement syndrome were enrolled and randomly divided into 2 experimental groups. The progressive resistance exercise protocol in experimental group I comprised shoulder internal rotation, while in experimental group II consisted of shoulder external rotation. The experimental groups worked out 3 days a week for 6 weeks. The experimental groups were compared with the control group consisting of 15 healthy athletes. The acromiohumeral distance was measured before and after the intervention using an ultrasound machine under the passive and active across no arm elevation and 45°of arm elevation. RESULTS: The acromiohumeral distance significantly increased in both experimental groups under the passive and active arm positions following the intervention (P < .001), with no significant differences detected between the experimental groups (P > .665). The paired comparisons of the acromiohumeral distance discrepancy indicated a significant difference between the control group and each experimental group under the active and passive arm positions (P < .001), while no significant difference was observed between the experimental groups (P > .999). CONCLUSIONS: The present study revealed, for the first time, that both progressive resistance exercise protocols involving either the shoulder internal or the external rotation increased the acromiohumeral distance in individuals with primary subacromial impingement syndrome and improved associated pain and disabilities.

Effects of Ultrasound-Guided Peritendinous and Intrabursal Corticosteroid Injections on Shoulder Tendon Elasticity: A Post Hoc Analysis of a Randomized Controlled Trial.

OBJECTIVES: The study aimed to investigate whether the shoulder tendons changed their elasticity after ultrasound-guided peritendinous or intrabursal corticosteroid injections. DESIGN: Post hoc secondary analysis of a double-blinded, randomized controlled study with 3 months of follow-up. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Patients with subacromial impingement syndrome (N=60). INTERVENTIONS: Patients with unilateral shoulder pain were randomly assigned to receive standard ultrasound-guided subacromial or dual-target corticosteroid injections. The supraspinatus tendons were exposed to 40 mg triamcinolone acetonide in the formal group, whereas the long head of the biceps brachii tendons (LHBT) and supraspinatus tendons were individually infiltrated by 20 mg triamcinolone acetonide in the latter group. Patients' bilateral shoulders were divided into group 1 (n=30, receiving standard subacromial injections), group 2 (n=30, receiving dual-target injections), and group 3 (n=60, without injections). MAIN OUTCOME MEASURES: Strain ratio of LHBT and supraspinatus tendons using ultrasound elastography. RESULTS: The repeated-measures analysis of variance revealed no intragroup difference of the strain ratio of the LHBT (P=.412 for group 1, P=.936 for group 2, P=.131 for group 3) and supraspinatus tendon (P=.309 for group 1, P=.067 for group 2, P=.860 for group 3) across the 3 time points. Treating group 3 as the reference, the linear mixed model revealed no significant changes in tendon elasticity after either the standard subacromial injection (P=.205 for the LHBT and P=.529 for the supraspinatus tendon) or the dual-target injection (P=.961 for the LHBT and P=.831 for the supraspinatus tendon). CONCLUSIONS: Elasticity of the LHBT and supraspinatus tendons is unlikely to change after a single dose of peritendinous or intrabursal corticosteroid injections. Future studies with a shorter follow-up interval are needed to validate whether corticosteroid injections can cause transient changes of the tendon's elasticity.

Comparison of low-level laser treatment and extracorporeal shock wave therapy in subacromial impingement syndrome: a randomized, prospective clinical study.

The aim of this study was to compare the efficacy of low-level laser treatment (LLLT) and extracorporeal shock wave therapy (ESWT) in the treatment of subacromial impingement syndrome (SIS). Seventy-one patients with subacromial impingement were randomly assigned to LLLT (n = 37) and ESWT (n = 34) groups. The patients received a total of 15 sessions of LLLT or once a week for 3 sessions of ESWT. All patients, before treatment, at the end of treatment, and 3 months after treatment, were evaluated with range of motion (ROM), visual analogue pain scale (VAS pain), Shoulder Pain and Disability Index (SPADI), Beck Depression and Anxiety Inventories, the Short Form Health Survey (SF-36), and Pittsburgh Sleep Quality Index (PSQI). In both groups, there was a significant improvement in all outcome measures (p < 0.05) except the mental health score in the LLLT group. ESWT group showed more improvements in terms of SPADI disability and total scores, PSQI, and physical-mental health scores at the end of treatment (p < 0.05). The improvement in VAS pain day and SPADI scores at the third month was significantly more evident in the ESWT group (p < 0.05). Both LLLT and ESWT treatments are effective in the treatment of SIS in the short-medium term and can be used in clinical practice. Future larger prospective clinical trials are needed to investigate the long-term efficacy and optimal treatment protocol of LLLT and ESWT in SIS.

The role of 18F-FDG PET/CT in the diagnosis of frozen shoulder.

PURPOSE: Frozen shoulder is characterized by pain and reduced passive movement capability, and the diagnose is made clinically. However, pain is the major symptom in the first stage before stiffness occurs, and the condition can be mistaken for subacromial impingement. This study explored the possibility to use positron emission tomography/computed tomography (PET/CT) with a 18F Flour-Deoxy-Glucose (FDG) tracer in the diagnostic process. METHODS: Eleven patients with frozen shoulder and 9 patients with subacromial impingement received a 18F-FDG PET/CT scan before being treated surgically. During arthroscopy, the diagnoses were confirmed. Images were blindly analyzed visually by two nuclear medicine physicians. Also, semi-quantified analysis applying a set of standard regions was performed, and standard uptake value in both shoulder regions was recorded. RESULTS: Both the visual description of the pictures and the semi-quantified analysis generally showed increased FDG uptake in the affected shoulder regions of patients that had frozen shoulder and no uptake in patients with subacromial impingement. Kappa for interobserver agreement in the visual assessments was 0.74. Sensitivity was 92% and specificity 93% of the visual assessment, 77% and 93%, respectively, of the semi-quantified analyses, and by combining the two types of analyses sensitivity was 100% and specificity was 93% for the distinction between frozen shoulders and subacromial impingement/unaffected shoulders. CONCLUSION: 18F-FDG PET/CT seems to be a valid method to diagnose frozen shoulder. This is clinically relevant in diagnostically challenging cases, for instance in the first phase of frozen shoulder, which can be difficult to distinguish from subacromial impingement. LEVEL OF EVIDENCE: II.

Inclinometer Reliability for Shoulder Ranges of Motion in Individuals With Subacromial Impingement Syndrome.

OBJECTIVE: This study aimed to determine the intra- and interrater reliability of active and passive range of motion in the shoulders of individuals with subacromial impingement syndrome using a digital inclinometer. METHODS: The raters evaluated active and passive range of motion in the shoulder of 50 individuals with unilateral subacromial impingement syndrome in movements including flexion, abduction, extension, external rotation in a neutral position, external rotation with the arm at 90° of abduction, and internal rotation with the arm at 90° of abduction. The tests were performed by 2 examiners on the same day, with a 10-minute interval, and were repeated by 1 examiner after a 2- to 4-day interval. Reliability was analyzed using the intraclass correlation coefficient (ICC2,3). RESULTS: There was moderate to excellent interrater (ICC2,3 = 0.50-0.95) and intrarater (ICC2,3 = 0.74-0.94) reliability. In the interrater analysis, the standard error of measurement (SEM) ranged from 4.1° to 10°, the percentage SEM (%SEM) ranged from 2% to 17%, and the minimum detectable change ranged from 9.5° to 23.4°. In the intrarater analysis, the SEM ranged from 4° to 9.2°, %SEM ranged from 3% to 14%, and the minimum detectable change ranged from 9.3° to 21.4°. CONCLUSION: The digital inclinometer showed moderate to excellent reliability for measuring active and passive range of motion in shoulders with unilateral subacromial impingement syndrome.

Exercise therapy may affect scapular position and motion in individuals with scapular dyskinesis: a systematic review of clinical trials.

BACKGROUND: Therapeutic exercise for scapular muscles is suggested to be effective in reducing shoulder pain in patients with rotator cuff disorders, whereas its effectiveness on scapular position and motion has remained unclear. Therefore, the aim of this systematic review was to investigate whether exercise therapy improves scapular position and motion in individuals with scapular dyskinesis. METHODS: This study is a wide systematic review including any type of clinical trial in which the effect of any type of therapeutic exercise, including scapular muscle strengthening, stretching, and scapular stabilization exercise, is investigated in adult participants. RESULTS: Twenty studies were included in this systematic review. Studies were categorized on the basis of the techniques they used to measure scapular position and motion and the included participants. Methodologic quality of the studies was assessed by the Cochrane tool of assessing the risk of bias. Eight studies used 3-dimensional techniques for measuring scapular motions. Among them, 5 studies showed significant effects of exercise on scapular motion, of which 3 studies investigated individuals with subacromial impingement syndrome (SIS). The other 12 studies used 2-dimensional measurement techniques, of which 8 studies reported significant effects of exercise on scapular position and motion both in SIS patients and in asymptomatic individuals. However, their methodologic quality was debatable. Therefore, there was conflicting evidence for the effect of exercise on scapular dyskinesis. CONCLUSION: There is a lack of evidence for beneficial effects of exercise in improving scapular position and motion in individuals with scapular dyskinesis. However, exercise is beneficial in reducing pain and disability in individuals with SIS.

Absolute and Relative Reliability of Pressure Pain Threshold Assessments in the Shoulder Muscles of Participants With and Without Unilateral Subacromial Impingement Syndrome.

OBJECTIVE: The purpose of this study was to determine the relative and absolute reliability of the pressure pain threshold (PPT) in the shoulder muscles of participants with and without unilateral subacromial impingement syndrome. METHODS: Study of intraday intra- and interrater and interday intrarater reliability. Fifty-two participants symptomatic for unilateral subacromial impingement syndrome were divided into 2 groups (SG1 and SG2) of 26 participants each, and 26 participants asymptomatic for shoulder pain took part in the study. Two raters assessed the PPT in 4 shoulder muscles. Each rater assessed symptomatic (SG1) and asymptomatic participants twice on the same day, and one of the raters on 2 different days (SG2). The intraclass correlation coefficient, standard error of measurement (SEM95% and SEM%), and minimum detectable change (MDC95% and MDC%) were calculated. RESULTS: Relative reliability was good or excellent for all assessments, as well as for both groups and raters (intraclass correlation coefficient: 0.87-0.98). The SEM95% values for intra- and interday intrarater measures were between 0.43 and 1.50 kgf/cm2 and SEM% between 6.76 and 12.86%, whereas MDC95% values ranged from 0.60 to 2.12 kgf/cm2 and MDC% from 9.56 to 18.18%. In interrater measures, SEM95% was between 0.58 and 0.77 kgf/cm2 and SEM% between 10.10% and 13.71%, whereas MDC95% varied from 0.82 to 1.08 kgf/cm2 and MDC% from 14.29% to 19.39%. CONCLUSION: Relative reliability was good or excellent. This study presents absolute reliability values that could be used as a reference in the clinical use of PPT.

Relationship Between Intensity of Neck Pain and Disability and Shoulder Pain and Disability in Individuals With Subacromial Impingement Symptoms: A Cross-Sectional Study.

OBJECTIVE: This study aimed to verify a possible relationship between shoulder disability and shoulder pain intensity and the variables related to cervical-spine dysfunction, and determine which of these can differentiate moderate to severe shoulder pain (>4 on a numerical rating scale [NRS]) from mild shoulder pain (≤4 on the NRS) in individuals with subacromial impingement symptoms. METHODS: One hundred and forty volunteers with shoulder pain were evaluated. Demographic information and variables related to the shoulder and neck were collected. Self-reported pain and disability of the shoulder and cervical spine were measured using the Shoulder Pain and Disability Index (SPADI) and Neck Disability Index (NDI) questionnaires, respectively. An NRS was used to measure pain in the shoulder and cervical spine. A purposeful modeling strategy was used to determine the best model to predict shoulder disability and shoulder pain (dependent variables). Multiple logistic regression analysis followed by receiver operating curve analysis was used to determine which variables better differentiated moderate to severe shoulder pain from mild shoulder pain. RESULTS: Variables such as Neck Disability Index (NDI) score (ß = 1.09, P = .00) and age (ß = -0.19, P = .03) were associated with the total SPADI score. Neck pain was significantly associated with shoulder pain (ß = 0.40, P = .00). The combination of variables predicting moderate to severe shoulder pain was total SPADI score (odds ratio [OR] = 1.15, P = .003), neck pain (OR = 3.20, P = .04), and age (OR = 1.01, P = .05). CONCLUSION: Our results demonstrate the important connection between shoulder- and neck-related symptoms in individuals with subacromial impingement symptoms.

Can the efficacy of subacromial corticosteroid injection be improved using a single- session mobilization treatment in subacromial impingement syndrome? A randomized single-blind controlled trial

Background/aim: The objective in this study is to assess the short-term effects of a single-session mobilization in addition to subacromial corticosteroid (SACS) injection in impingement syndrome. Materials and methods: The study was designed as a prospective randomized controlled single-blind, parallel group clinical trial. Patients (totally 84) were divided randomly into two groups equally. Forty-two patients in Group 1 received mobilization and SACS injection, whereas 42 patients in Group 2 only received SACS injections. A single SACS injection was applied in all patients. Mobilization was administered as a single session right after SACS injection. Patients' evaluations were performed measuring active range of motion (AROM), visual analogue scale (VAS) during activity and rest, and Disabilities of Arm, Shoulder, and Hand Score (DASH) prior to treatment and in the first and fourth weeks following the treatment. Results: Both groups showed significant improvement in terms of AROM, VAS, and DASH scores in each evaluation step (P < 0.05). Visual analogue scale activity in the first week was significantly better in Group 1 (P = 0.028). Also, flexion and abduction degrees showed significantly better outcomes in Group 1 (P = 0.007, P = 0.036). Conclusion: Addition of single-session mobilization might provide rapid improvement in flexion and abduction as well as early pain relief following SACS injections.

Comparison of glenohumeral joint rotation between asymptomatic subjects and patients with subacromial impingement syndrome using cine-magnetic resonance imaging: a cross-sectional study.

BACKGROUND: The purpose of this study to compare glenohumeral joint motion during active shoulder axial rotation between subacromial impingement syndrome (SIS) shoulders and asymptomatic shoulders using cine-magnetic resonance imaging (cine-MRI). Measurement of glenohumeral joint motion via manual intervention does not assess the usual glenohumeral joint motion, and the glenoid surface cannot be confirmed manually. However, cine-MRI can produce clear images of glenohumeral joint rotation. Therefore, we sought to measure the active ROM of the glenohumeral rotation using cine-MRI. METHODS: Seventy-three shoulders in 42 asymptomatic volunteers and 110 SIS shoulders in 103 consecutive patients were included in this study. We evaluated 36 matched pairs (72 shoulders in total) adjusting for baseline characteristics with propensity score matching method. The patients underwent cine-MRI during axial rotation of the adducted arm. During imaging, participants rotated their shoulder from the maximum internal rotation to the maximum external rotation over the first 10 s and then back to the maximum internal rotation over the subsequent 10 s. We assessed internal/external rotation, and compared the asymptomatic and SIS shoulders in this regard. Evaluation of rotation angles was performed on a series of axial images through the humeral head center. RESULTS: The mean internal rotation angles of the asymptomatic and patient groups were 55° ± 10° and 41° ± 23°, respectively, (P = .002; 95% Confidence Interval [CI], 51-58 vs 33-49); the mean external rotation angles were 47° ± 15° and 21° ± 25°, respectively, (P < .001; CI, 42-52 vs 13-29). CONCLUSIONS: Compared to asymptomatic shoulders, SIS shoulders showed significantly restricted glenohumeral rotation as determined by cine-MRI. Our results suggested that the significant limitation of active glenohumeral rotation might be associated with rotator cuff dysfunction.

A Systematic Review and Meta-analysis of Functional Shoulder Impairment After Latissimus Dorsi Breast Reconstruction.

PURPOSE: The latissimus dorsi flap (LDF) is a very reliable flap and may be used for a multitude of reconstructive purposes. It is widely used for breast reconstruction when performed. It has few complications, except for a possible impact on shoulder function. The aims of this study were to evaluate the validity of the literature by investigating the level of evidence and to perform a meta-analysis. METHODS: A systematic literature search was conducted using the databases PubMed, Scopus, and Web of Science. Predictor variables were shoulder function after breast reconstruction with the LDF. Articles were chosen according to 4 different outcomes: shoulder range of motion (ROM), shoulder strength, DASH score, and subjective evaluation. RESULTS: Twenty-six articles were found, including 1045 patients: 8 level II, 16 level III, 1 level IV, and 1 level V articles. The meta-analysis showed that both ROMs for flexion and abduction are significantly impaired at less than or at 3 months of follow-up. CONCLUSIONS: There are several influencing factors, such as age, smoking, obesity, radiotherapy, and physiotherapy. Moreover, the impact on shoulder function seemed influenced by the type of thoracodorsal vessel-based flap. From the level of evidence analysis, there is a tendency that the LDF transfer does affect shoulder function. This limitation seems to be minimal, and few patients experience a major impact on shoulder function. However, the existing literature on total shoulder impairment after breast reconstruction with LDF is insufficient to draw any final conclusion. There is a need for future studies and current articles that suggest that the initial measurement should be performed preoperatively (preferably at the time of diagnosis or initial biopsy) and follow-ups with measurements at 6, 12, and 24 months (long-term effect) after surgery. We recommend measurements of both operated and nonoperated sides. Each measurement should be accompanied by a history with special emphasis on shoulder function. The methods of measuring outcomes of recommendation are DASH score, ROM with use of a goniometer preferably by a physiotherapist or a health care professional trained by a physiotherapist, and strength measured by, for example, a handheld dynamometer.

Electromyographic analysis of shoulder girdle muscle activation while performing a forehand topspin in elite table tennis athletes with and without shoulder impingement syndrome.

BACKGROUND: Shoulder impingement syndrome is considered to be associated with an altered muscular activity, which is related to strategy changes in the movement plan. The present study aimed to investigate the differences in timing and intensity of activity of shoulder girdle muscles while performing a forehand topspin loop between elite table tennis players with and without shoulder impingement syndrome. The timing and activity amplitude of these shoulder girdle muscles have not been evaluated in other studies in table tennis elite athletes. METHODS: Activation timing and activity levels of the upper trapezius, lower trapezius, and serratus anterior, anterior deltoid, supraspinatus, and biceps brachii muscles were measured in 30 table tennis players (Premier League tournament level or higher) with shoulder impingement syndrome and compared with 30 same-level healthy players while performing the forehand topspin loop. RESULTS: The results indicated that the activity levels of the serratus anterior (P = .007) and supraspinatus (P = .001) muscles significantly decreased; however, the activity level of the upper trapezius significantly increased in the impingement compared with the healthy group (P = .009). The serratus anterior (P = .001) was activated significantly later, but the upper trapezius (P = .004) was activated significantly earlier in the impingement group. CONCLUSION: Results of the present study support the theory that the activation and sequence of recruiting of the shoulder muscles are altered in people with impingement symptoms, suggesting that impingement syndrome may be associated with disturbed timing and activity level of shoulder girdle muscles.

Psychometric evaluation of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function and Pain Interference Computer Adaptive Test for subacromial impingement syndrome.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Computer Adaptive Test (CAT) was previously validated for rotator cuff disease and shoulder instability. This study evaluated the psychometric properties of the PROMIS Physical Function (PF) CAT, PROMIS Pain Interference (PI) CAT, and the American Shoulder and Elbow Surgeons (ASES) Shoulder Function Score for subacromial impingement syndrome. METHODS: PROMIS PF CAT, PI CAT, and ASES (Pain, Function, Total) were collected on all visits for 2 surgeons between January 2016 and August 2016. New patients, aged 18 years and older, were selected by International Classification of Diseases code for impingement syndrome of the shoulder. The mean number of questions answered determined efficiency. Person-item maps were created to determine ceiling and floor effects as well as person reliability. Convergent validity was determined by comparison of PROMIS domains to ASES scores with Pearson correlations. RESULTS: For PROMIS PF CAT, the mean number of items answered was 4.54 (range 4-12). The ceiling effect was 1.56%, and the floor effect was 3.13%. The person reliability was 0.94. Pearson correlation coefficients between the PF CAT and ASES were 0.664 (ASES Function), 0.426 (ASES Pain), and 0.649 (ASES Total). For PROMIS PI CAT, the mean number of items answered was 4.27 (range 3-11). The ceiling effect was 4.69%, and the floor effect was 8.33%. The person reliability was 0.92. Pearson correlation coefficients between the PI CAT and ASES were: 0.667 (ASES Function), 0.594 (ASES Pain), and 0.729 (ASES Total). CONCLUSIONS: The psychometric properties of PROMIS PF and PI CATs were favorable for subacromial impingement syndrome.

Analysis of impingement-free range of motion of the glenohumeral joint after reverse total shoulder arthroplasty using three different implant models.

BACKGROUND: This study aimed to investigate impingement-free range of motion (ROM) of the glenohumeral joint following reverse total shoulder arthroplasty (RTSA) with three types of implant models using computational motion analysis. METHODS: Three-dimensional (3D) scapulohumeral models were created from preoperative computed tomography (CT) images of seven patients by using visualization and computer-aided design software. Three types of implant designs, namely, typical medialization, in between, and lateralization implants, were used for the reconstruction of 3D model; each design was designated as group I, II, and III, respectively. All possible combinations of virtual surgeries were evaluated for impingement-free ROM in all three groups. Maximal ROMs were compared. The effect of implant positions on ROM of the shoulder joints were investigated in each group. RESULTS: The all lateralization group (group III) showed significantly greatest maximal adduction, abduction and external rotation (ER). Adduction and abduction were significantly increased by the glenoid component inferior translation in all three groups. (In group I, p < 0.001 for adduction, p = 0.002 for abduction, respectively; in group II, p = 0.025, p < 0.001, respectively; in group III, p = 0.038, p = 0.011, respectively). Increasing humerus retroversion might have some effect on increasing abduction. In group II and III, internal rotation (IR) and ER were significantly affected by the humerus retroversion (in group II, p = 0.033 for IR, p = 0.007 for ER, respectively; in group III, p = 0.004, p < 0.001, respectively). In group III, ER was also significantly affected by the glenoid component inferior translation (p = 0.003). CONCLUSIONS: Lateralization design model showed greatest ROM of the shoulder joint. The effects of implant positions on impingement-free ROM exhibited different tendencies between medialization and lateralization implant models. Humerus retroversion affected both IR and ER, especially in lateralization design. Increasing glenoid inferior translation increases both adduction and abduction regardless of implant designs.

Radiological and biomechanical assessment of displaced greater tuberosity fractures.

PURPOSE: Greater tuberosity fractures are challenging lesions concerning decision-making. In order to improve our treatment algorithm, we developed a new method, which allows predicting a possible subacromial conflict on standard anteroposterior radiographs, considering not only the displacement of the fragment but also the width of the subacromial space. METHODS: The measurement technique consisted of drawing three concentric circles on true anteroposterior radiographs. The inner circle (radius Rh) perfectly matched the humeral head surface. The medial circle (radius Rt) was tangent to the greater tuberosity, and the outer circle (radius Ra) touched the undersurface of the acromion. The ratio Rt/Rh, which describes how much the greater tuberosity projects above the articular surface, and the relationship (Rt-Rh)/(Ra-Rh), which quantifies the space occupied by the greater tuberosity under the acromion, were calculated and called Greater Tuberosity Index and Impingement Index, respectively. Five dry humeri were used to assess the influence of rotation and abduction on the Greater Tuberosity Index. The radiographs of 80 shoulders without any osseous pathology were analyzed to obtain reference values for both indices. Finally, greater tuberosity fractures with different displacements were created in five cadaver specimens, and subacromial impingement was correlated with these parameters. RESULTS: On anteroposterior radiographs, the greater tuberosity was most prominent in neutral rotation, regardless of abduction. In shoulders without osseous pathology, the Greater Tuberosity Index and the Impingement Index averaged 1.15 (range 1.06-1.28) and 0.46 (range 0.21-0.67). In the biomechanical experiments, the Impingement Index was a better discriminator for subacromial impingement than the Greater Tuberosity Index. A fracture with a displacement corresponding to an Impingement Index of 0.71 or greater was associated with subacromial impingement. CONCLUSIONS: Reduction of a displaced greater tuberosity fragment should be considered if the Impingement Index is 0.7 or greater. The measurement method is simple and reliable and has the potential to be used for the assessment of subacromial impingement in other conditions.

Attrition of rotator cuff without progression to tears during 2-5 years of conservative treatment for impingement syndrome.

PURPOSE: The purpose of this study was to investigate the natural history of intact rotator cuff in impingement syndrome patients with concomitant spur protruding from the undersurface of acromion. METHODS: This retrospective study included 119 patients with an intact rotator cuff who underwent conservative treatment for a spur protruding from the undersurface of the acromion. The protruded spur was defined as a trapezoid- or tetragon-shaped bony protrusion with a downward peak extending more than 3 mm in length from the baseline drawn along the acromial undersurface on the coronal view of magnetic resonance imaging (MRI) or computed tomography arthrography (CTA). Functional outcomes were evaluated by the visual analogue scale for pain, subjective shoulder value, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and active range of motion (ROM). To evaluate cuff integrity, follow-up MRI, CTA, or ultrasound were performed at least 2 years after the initial presentation. RESULTS: No new rotator cuff tears were noted in any patient during the follow-up imaging studies. However, 18 patients (15%) underwent arthroscopic acromioplasty during the study period. During the arthroscopic examinations, moderate to severe attrition of the cuff was identified, although no tears were seen. At the final follow-up, pain level and shoulder function, including ROM, showed satisfactory outcomes. CONCLUSION: Spurs protruding from the acromial undersurface did not lead to rotator cuff tears during 2-5 years of conservative treatment. However, attrition of the rotator cuff was found during arthroscopic acromioplasty, suggesting that the protruding spurs caused extrinsic impingement of the cuff. LEVEL OF EVIDENCE: Therapeutic case series Level IV.

Comparison of Scapular Mechanics After Activity With and Without a Targeted Compression Garment.

Muscle fatigue can result in scapular dyskinesis, which has been implicated in impingement, labral injury, and rotator cuff injury. This study evaluated the ability of a compression shirt to maintain scapular alignment after fatiguing of periscapular musculature. Subjects' scapular movements were monitored before and after a periscapular muscle- fatiguing exercise program. In the anterior and posterior tilt and medial and lateral rotation dimensions, control and shirt subjects both exhibited differences between the prefatigue and postfatigue measurements throughout humeral elevation. In the retraction and protraction dimension, control subjects exhibited differences between prefatigue and postfatigue measurements for a large portion of elevation, while shirt subjects only had different measurements toward the extreme of shoulder flexion. Thus the shirt does not stabilize the scapula in the anterior and posterior tilt and medial and lateral rotation dimensions. In the retraction and protraction dimension, the shirt provides stability to the scapula and maintains prefatigue position. It is currently unclear if preserving one plane of scapular motion has clinical significance. (Journal of Surgical Orthopaedic Advances 28(1):18-23, 2019).

Effect of Balance Taping Using Kinesiology Tape and Cross Taping on Shoulder Impingement Syndrome: A Case Report.

Background and objectives: Shoulder impingement syndrome (SIS) is the most common disorder among people with shoulder pain. The purpose of this case report was to investigate the effect of the combined application of balance taping using kinesiology tape and cross taping on a part-time worker with SIS. Case Report: Combined balance taping and cross taping was applied for 3 weeks (average, 16 hours per day) on a part-time worker with severe pain and a limited range of motion (ROM) in the shoulder who had visual analogue scale (VAS) pain scores of 7 and 8 out of 10 for shoulder flexion and abduction, respectively, and pain and disability scores of the Shoulder Pain Disability Index (SPADI) of 37 out of 50 and 29 out of 80, respectively. After the combined application of balance taping and cross taping, the VAS pain scores for shoulder flexion and abduction decreased from 7 to 0 and from 8 to 0, respectively, and the ROM increased to a normal range. The SPADI pain score decreased from 37 to 2, and the disability score decreased from 29 to 1. Shoulder activity level also increased, and the patient was able to return to his part-time job. Conclusions: We suggest combined application of balance taping and cross taping as an effective treatment for part-time workers with SIS.

Shoulder Injuries in the Overhead-Throwing Athlete: Epidemiology, Mechanisms of Injury, and Imaging Findings.

The unparalleled velocity achieved by overhead throwers subjects the shoulder to extreme forces, resulting in both adaptive changes and pathologic findings that can be detected at imaging. A key biomechanical principle of throwing is achieving maximum external rotation, which initially leads to adaptive changes that may result in a pathologic cascade of injuries. In addition to the well-established concepts of glenohumeral internal rotation deficit and internal impingement, osseous and soft-tissue injuries of the shoulder unique to overhead athletes are illustrated. The epidemiology and biomechanics of throwing injuries are reviewed, and examples from the authors' institutional experience with competitive, collegiate, and professional baseball players are provided to demonstrate the constellation of unique imaging findings seen in overhead throwing athletes. Given the widespread popularity of baseball, and other sports relying on overhead throwing motions at all playing levels from recreational to professional, it is important for radiologists in various practice settings to be familiar with the special mechanisms, locations, and types of shoulder injuries seen in the overhead throwing population. © RSNA, 2018.